Air curtain with a main air stream and an auxiliary air stream, and a device and method for producing the same

ABSTRACT

Air curtain with an auxiliary stream, which is used to protect rooms against the impact of external factors (weather conditions, volatile substances, particulate solids, insects etc.), as well as to protect rooms against the outflow of internal air outside. The air exhausts form at least two separate air streams, the main stream is directed towards the construction hole at the limit of the room, while the auxiliary stream is directed into the room at an acute angle in relation to the plane of the construction hole. The main stream and the auxiliary stream do not cross each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C§119 and the Paris Convention Treaty, this application claims the benefit of Polish Patent Application No. P 387085 filed Jan. 21, 2009, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an air curtain having an auxiliary stream, which is used to protect rooms against the impact of external factors (weather conditions, volatile substances, particulate solids, insects, etc.), as well as to protect rooms against the outflow of internal air by use of an air stream that separates an inner zone from an outer zone.

The solution proposed in the present invention protects against the particularly unfavorable external factor which is the inflow of the external air with physical parameters (density, pressure, velocity, temperature etc.) that are different from the desired levels. In the case when the temperature of the external air is lower than the temperature of the room, a heated jet of air is directed to the outside to prevent an increased inflow of external air, which would otherwise results in high losses of temperature and increased demand for thermal energy. Similarly, in the case when the temperature of external air is higher than the temperature of the air in the room, a cooled jet of air is directed to the outside to prevent an increased inflow of external air, which would otherwise results in high increases of temperature and increased energy consumption for cooling.

2. Description of the Related Art

EP 1462730 A1 refers to a device that generates an air curtain within the area of a construction hole such as, particularly, gates, doors or similar structures. The device consists of at least one apparatus generating the air stream, at least one heat exchanger (heater or radiator) and directional components.

The device is used to generate an air curtain consisting of two adjacent partial streams—one of the partial streams is generated at a higher flow velocity than the other. Each partial stream may be generated by its own individual air fence. The air fences are set in such a way as to provide various velocities of the air flow. A variation of the mentioned solution is based on the concept that each air fence generating a partial stream is equipped with at least one dedicated apparatus which generates the air stream.

Another known device mentioned in EP 0645588 B1 refers to an air curtain that generates two parallel primary air streams using at least two blowing elements, situated in parallel, adjacent to each other. Both streams have the same direction and velocity, and between the two mentioned blowing elements there is at least one blowing element that generates an intermediate stream which is directed parallel to the primary streams and has the same velocity as the primary streams.

The known solutions for air curtains generating one or more air streams, directed parallel to the plane of the construction hole, are based on the concept that the part of the air stream in the bottom zone deviates from the vertical plane of the hole. The deviation of the stream to the outside of the room results in the outflow of the air from the curtain, thus generating a significant loss of the thermal energy of the stream. When the air stream is deviated towards the interior of the room, as a consequence of the velocity of the flow, an area of lower pressure (vacuum) is created on the external edge of the stream, which results in the sucking of the external air into the room. This invention is aimed at remedying the above described problems.

SUMMARY OF THE INVENTION

In the curtain as per the invention air exhausts form at least two separate air streams. The main stream is directed towards the construction hole (an opening for doors, gates, windows, etc.) at the limit of the room, while the auxiliary stream (the objective of which is to turn up the main stream into the room in a controlled way) is directed into the room at an acute angle in relation to the plane of the construction hole. Both the main and auxiliary streams do not cross. The curtain can be placed at the top or on the side of the construction hole. Each stream, the main and the auxiliary, is advantageously generated by at least one fan separate for each stream. The curtain advantageously has at least one heat exchanger which sets the required thermal parameters for at least one air stream. The curtain advantageously is also equipped with at least one filter for the sucked-in air. The additional directional element which directs the air stream advantageously is added to at least one of the air exhausts. The additional directional element advantageously is mobile.

The main stream is directed towards the construction hole at the limit of the room. Its objective is to separate two zones of different temperatures or different physical parameters, present near the area of the construction hole. According to the laws of physics, adequate velocity of the flowing auxiliary stream (directed into the room at an acute angle in relation to the plane of the construction hole) results in the phenomenon of “induction” (suction) of the air. The velocity of the auxiliary stream creates under pressure (vacuum) along its edge, which produces a turbulent mixing zone. The mixing zone lifts up the still layers of the air located below the auxiliary stream. The layers of the air confined in the space between the streams, lifted up by the kinetic energy produced by the auxiliary stream, create the phenomenon of sucking the main stream around the floor area, towards the interior of the room, in a controlled way. Such phenomenon may be additionally strengthened by the difference in temperatures of the air streams. If the room's internal temperature exceeds the external temperature, is would be particularly advantageous to use the auxiliary stream and/or the main stream whose temperature is equal to or higher than the internal temperature. Heating up the auxiliary stream to a higher temperature enables the strengthening of the mentioned phenomenon of directing the curtain's stream towards the interior of the room thanks to the effect of convection (lifting up of warmer air masses). Such solution to the problem enables the reducing of the auxiliary stream velocity, without hampering the performance of the solution as per the invention.

Using the solution proposed in the present invention provides a uniform distribution of the main stream within the entire area of the plane of the construction hole, down to its bottom edge. Due to eliminating of the negative phenomenon related to the outflow of a significant amount of the main stream out of the room and, simultaneously, of unwanted inflow of external air into the room, the use of air curtain of the invention increases the effectiveness of performance and protection of the room, and thermal protection in particular.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described hereinbelow with reference to accompanying drawings, in which:

FIG. 1 shows a general view of the curtain;

FIG. 2 shows a bottom view of the curtain; and

FIG. 3 shows the operational principle of the air curtain in a schematic way.

In the drawings, 1 represents air intake, 2—filter for the sucked-in air, 3—heat exchanger, 4—fan, 5—expansion chamber, 6—air exhaust for the main stream, 7—air exhaust for the auxiliary stream, 8—additional directional element for the main air stream; 9—additional directional element for the auxiliary air stream, A—main air stream, B—space between air streams, and C—auxiliary air stream.

DETAILED DESCRIPTION OF THE INVENTION

The air curtain has an air intake 1 which sucks in the external air, and the air filter 2 which cleans the sucked-in air. The curtain has a plate-fin heat exchanger 3 which, depending on the medium applied, is used to set appropriate thermal parameters for the air that flows round the exchanger 3, i.e., heat it up or cool it down to the desired temperature. The air is sucked through an axial-flow fan 4. The fan 4 generates pressure on the pumping side which contains the expansion chamber 5. The air expanded in the expansion chamber 5 is directed to the air exhausts 6, and 7 formed by a common element. Then, the air exhausts 6, and 7 form the following: the main steam A and the auxiliary stream C. Directional elements 8, 9 for the air streams A, C, are installed at the ends of the air exhausts 6, and 7.

This invention is not to be limited to the specific embodiments disclosed herein and modifications for various applications and other embodiments are intended to be included within the scope of the appended claims. While this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.

All publications and patent applications mentioned in this specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application mentioned in this specification was specifically and individually indicated to be incorporated by reference. 

1. An air curtain comprising at least two separate air streams: a main air stream and an auxiliary air stream, wherein said main air stream is directed toward a construction hole at a limit of a room; said auxiliary air stream is directed at an acute angle in relation to the plane of the construction hole; and said main air stream and said auxiliary air stream do not cross each other.
 2. The air curtain of claim 1, wherein said main air stream and said auxiliary air stream are generated separately from each other.
 3. The air curtain of claim 1, wherein at least said main air stream or at least said auxiliary air stream have separate thermal parameters.
 4. The air curtain of claim 1, wherein said main air stream and said auxiliary air stream are filtered.
 5. The air curtain of claim 1, wherein said main air stream and said auxiliary air stream impinge on at least one directional element.
 6. The air curtain of claim 1, wherein said main air stream and said auxiliary air stream impinge on at least one moving directional element.
 7. A device for producing an air curtain, the air curtain comprising at least two separate air streams: a main air stream and an auxiliary air stream, the device comprising an air intake, at least a fan, and at least two air exhausts, wherein air entering said air intake and exiting said exhausts forms at least two separate air streams: a main air stream and an auxiliary air stream, wherein said main air stream is directed toward a construction hole at a limit of a room; said auxiliary air stream is directed at an acute angle in relation to the plane of the construction hole; and said main air stream and said auxiliary air stream do not cross each other.
 8. The device of claim 7, wherein said fan generates said main air stream and said auxiliary air stream separately from one another.
 9. The device of claim 7 further comprising a heat exchanger, said heat exchanger setting thermal parameters of at least said main air stream or at least said auxiliary air stream.
 10. The device of claim 7 further comprising an air filter that filters said air entering said air intake.
 11. The device of claim 7 further comprising at least one directional element, wherein said directional element is directly connected to at least one said air exhaust and directs said main air stream and/or said auxiliary air stream.
 12. The device of claim 7, further comprising at least one moving directional element, wherein said moving directional element is directly connected to at least one said air exhaust, is mobile, and directs said main air stream and/or said auxiliary air stream.
 13. A method for producing the air curtain of claim 1 using the device of claim 7, comprising passing electric current through said air fan whereby intaking air though said air intake and outputting air through said air exhausts and generating said main air stream and said auxiliary air stream.
 14. The method of claim 13, wherein said fan generates said main air stream and said auxiliary air stream separately from one another.
 15. The method of claim 13 further comprising setting thermal parameters of at least said main air stream or at least said auxiliary air stream using a heat exchanger.
 16. The method of claim 13 further comprising filtering said air entering said air intake and outputting filtered air as said main air stream and said auxiliary air stream.
 17. The method of claim 13 further comprising directing said main air stream and/or said auxiliary air stream towards at least one directional element.
 18. The method of claim 13, further comprising directing said main air stream and/or said auxiliary air stream towards at least one moving directional element. 